If you’re trying to search the web for pirated copies of Xbox games, Microsoft’s Bing is apparently the way to go.

This week, Google updated its transparency reports to show which copyright owners most frequently ask Google to remove links to infringing content. Microsoft is by far the most active rights holder, with more than 2.5 million takedown requests since July 2011, the new data shows. A company called Marketly, which issues takedown requests on Microsoft’s behalf, was also the top reporting organization last month.

But as TechDirt’s Mike Masnick points out, Microsoft isn’t always so aggressive when it comes to policing its own Bing search engine. By looking at recent takedown requests that Marketly sent to Google, Masnick found that Bing still harbors some links to pirated Xbox 360 games, even after they’ve vanished from Google:

Now, it seems pretty reasonable to assume that if Marketly is sending a takedown to Google to get such a link taken out of its search engine, on behalf of Microsoft, that it quite likely is issuing the same kind of takedown to Microsoft’s Bing (hell, you’d perhaps think that Microsoft could just pull the link without a takedown). And yet… the site, which Microsoft supposedly wants to disappear, is gone from Google, but found easily on Bing.

In fairness, Microsoft does police itself for pirated content. When I searched for piracy terms such as “Windows 7 torrent,” I found that Bing and Google had both removed the same search results. I also found some cases where Bing was more militant than Google about piracy links, such as with this result on Bing and Google. The issue appears to be with some recent takedown requests in which Bing isn’t moving as quickly as Google. That may be understandable, given that Google is a more popular search engine than Bing, but it doesn’t look great for Microsoft.

In any case, these takedowns aren’t a foolproof way of hiding piracy. That “Windows 7 torrent” search I mentioned before? It still turns up plenty of results on both search engines.